Low levels of Vitamin D, 25 Hydroxy are associated with increased risk of CVD events and death due to heart failure, sudden cardiac death, and stroke. The cardiovascular impact of low vitamin D is through activation of the renin-angiotensin-aldosterone system, as well as through increased parathyroid hormone levels (which predispose individuals to increased insulin resistance associated with diabetes, hypertension, inflammation, and increased cardiovascular risk).
Vitamin D, 25 Hydroxy is the main form of vitamin D circulating in blood and the best indicator of vitamin D deficiency or excess. Vitamin D tests using liquid chromatography, tandem mass spectrometry (LC/MS/MS) may also provide the concentration of vitamin D2 and D3 which, when added together, equal the total vitamin D concentration.